Prof. Whiteley qualified as a doctor at St Bartholomew's Hospital London in 1986. Following his training as a surgeon, in 1992 he began specializing in vascular surgery. In 1994 he completed his Masters in Surgery, and became a lecturer at Oxford University in 1995. In 1998 he was appointed a consultant vascular surgeon in Guildford. In March 1999 he performed the first UK keyhole surgery to eliminate varicose veins. In 2000 he, alongside Judy Holdstock, invented the TRLOP to treat perforating veins using a more advanced keyhole technique. In 2013 Whiteley was named a Visiting Professor at the University of Surrey.

Prof. Whiteley has pioneered several techniques and developed treatments along the course of his surgical career. He performed the first endovenous surgery for varicose veins in the UK in March 1999, the first microwave closure of varicose veins in Europe in February 2019, and the first Sononvein (HIFU - High-Intensity Focused Ultrasound) treatment in the UK in May 2019.

He is the founder of The Whiteley Clinic, a rapidly expanding medical clinic that specialises in Varicose Veins and minimally invasive venous surgery. He is also the founder of The College of Phlebology, an international group for doctors, nurses, vascular scientists and technologists to discuss venous issues and find educational support.

In 2013, Professor Whiteley set up the Leg Ulcer Charity, a UK national charity which aims to help patients with finding a cure for their leg ulcers. He has also sponsored PhD students and an MD position, and is highly involved with training and support. Mark Whiteley and his team have been at the forefront of developments in this field over the last decade and have won international, national and regional prizes for their research into vein treatments.